Method of making a sand mold

ABSTRACT

Bottomless cope and drag boxes mounted on a turntable are cleaned, assembled upon a pattern plate, turned on edge and clamped between closure platens and filled with molding sand. The platens are then advanced into the boxes to compress the sand against the patterns to form molds. Upon withdrawal of the platens, a sprue hole is made, the assembly is rotated to horizontal, and the boxes and contained molds are separated from the pattern plate, which is then withdrawn. After insertion of cores, if any, the boxes and molds are re-closed. An elevator rises through a withdrawal yoke into engagement with the mold whereupon a complementary platen opposing the elevator forces the sand mold downwardly from the boxes and into the plane of the yoke to the level of a withdrawal table onto which the yoke draws the mold, leaving the boxes empty for repetition of the process.

United States Patent [191 Fellows METHOD OF MAKING A SAND MOLD [76]Inventor: Harrison E. Fellows, Clearwater Lake, Wis. 54518 [22] Filed:Jan. 28, 1971 [21] Appl. No.: 110,654

Related U.S.'Application Data [62] Division of Ser. No. 790,072, Jan. 9,1969, Pat. No.

[56] References Cited UNITED STATES PATENTS 3,556,196 11/1971 Buhler "164/40 X. 3,229,336 l/1966 Hunter et al ..164/200 X 3,303,535 2/1967Rearwin et al. ..l64/l72 3,433,285 3/1969 Fellows ..l64/200 X STATION I[111 3,730,250 [4 1 May 1,1973

Primary Examiner-J. Spencer Overholser Assistant Examiner-John E.Roethel Attorney-Wheeler, House & Wheeler 57 ABSTRACT Bottomless copeand drag boxes mounted on a tumtable are cleaned, assembled upon apattern plate, turned on edge and clamped between closure platens andfilled with molding sand. The platens are then advance d into the boxesto compress the sand against the patterns to form molds. Upon withdrawalof the platens, a sprue hole is made, the assembly is rotated tohorizontal, and the boxes and contained molds are separated from thepattern plate, which is then withdrawn. After insertion of cores, ifany, the boxes and molds are re-closed. An elevator rises through awithdrawal yoke into engagement with the mold whereupon a complementaryplaten opposing the elevator forces the sand mold downwardly from theboxes and into the plane of the yoke to the level of a withdrawal tableonto which the yoke draws the mold, leaving the boxes empty forrepetition of the process.

6 Claims, 25 Drawing Figures STAT \ON :1

STATmNm.

STATION 3! Patented May '1, 1973 7 Sheets-Sheet 1 H zofrliw Patented May1, 1973 7 Sheets-Sheet 4.

iuvefl'roil Haze/501v: Fzuows 31 W, W, M1

Patented May 1, 1973 7 Sheets-Sheet 5 ATTOINEH Pgtented May 1, 1973 '7Sheets-Sheet 6 @ALLMQA,

ATTORNEY METHOD OF MAKING A SAND MOLD This application is a division ofSer. No. 790,072, filed Jan. 9, I969, and now US. Pat. No. 3,589,431.

BACKGROUND OF INVENTION This application is a companion to myapplication Ser. No. 476,090, filed July 30, 1965 and now US. Pat. No.3,433,285.

There are molding machines which produce a drag mold and then roll overto make a cope mold. The disadvantage of such devices lies in the factthat the drag mold is made against an unsupported pattern which willdeflect under some conditions. It is also known to make both moldssimultaneously by filling the form through the drag cavity from theside. In such devices of this character as I am acquainted with, thesand from an overhead magazine has to be forced through a bent pipe orconduit to enter the drag cavity in this manner and there isconsiderable friction and sometimes inadequate filling.

SUMMARY OF INVENTION The limited rotation of the mold boxes in theinstant device presents the mold cavities simultaneously to separatefiller spouts to receive sand directly from overhead magazine means ofthe type disclosed in my prior application above identified. Thecompression of the sand in the respective boxes also occurssimultaneously by platensoperating equally and oppositely to giveuniform mold density in the respective boxes.

The boxes within which the molds are formed are pivotally attached tooperating rams and slidably mounted in guides having trunnions carriedby arms cantilevered from the indexing table. This arrangement permitsthe parts to be in the desired position, whether it be vertical orhorizontal, at the respective stations, hydromotors preferably beingused to effect the required bodily rotation on the trunnions.

For withdrawing the finished molds, a yoke embracing the molds travelsacross a withdrawal table. The molds are lowered to the level of thetable on an elevator which rises through the yoke into mold engagement.When the elevator engages a mold from beneath, the mold is engaged fromabove by a platen complementary to the elevator and which descends toforce the mold and elevator downwardly into the plane of the yoke at thelevel of the table.

Another feature of the invention is an arrangement whereby a three-wayvalve permits the application of pressure through the exhaust vents tofacilitate the releasing of the sand molds from the boxes.

BRIEF DESCRIPTION OF DRAWINGS FIG. I is a diagrammatic plan view ofparts of mold making equipment embodying the invention, the superstructure being removed to expose most of the mechanism at the levelindicated by the line 1-1 of FIG. 2.

FIG. 2 is a diagrammatic view taken in section on the line 2-2 of FIG.1.

FIG. 3 is an enlarged detail view showing in side elevation thestructure at Station II.

FIG. 4 is a view in vertical radial section through the mold fillingstructure in FIG. 3.

FIG. 6 is a fragmentary detail view on an enlarged scale taken insection through one of the vent fittings.

FIG. 7 is an enlarged fragmentary detail view in generally horizontalsection through the parts of Station I.

FIG. 8 is a view in perspective fragmentarily illustratingdiagrammatically and in mutually separated positions the mold boxes andassociated parts.

FIGS. 9 to 25 are diagrammatic views showing procedural steps in which:

FIG. 9 shows air blast cleaning of sand from the mold boxes and patternsin preparation for re-use at Station I.

FIG. 10 shows the pattern plate advanced to position between theseparated mold boxes at Station I.

FIG. 11 shows the mold boxes closed upon the pattern plate at Station I.

FIG. 12 shows the open ended mold boxes and pattern plate assemblyrotated ninety degrees to receive the sand through the ends of the boxesat Station Il.

FIG. 13 shows the closure plates advancing to close.

the open ends of the mold boxes to provide closed chambers into whichthe sand can be blown at Stationv FIG. 14 shows the boxes closed and thesand being delivered into them about the pattern as at Station II.

FIG. 15 shows the sand within the boxes being subjected to compressionagainst the pattern as at Station II.

force the pattern plate back to stored position at Station III.

FIG. 19 shows the pattern plate in stored position to i which it hasbeen forced by III.

FIG. 20 shows placement of the cores in the sand mold at Station IV. I

FIG. 21 shows the two sections of the sand mold closed upon the core atStation IV.

the extended ram at Station FIG. 22 shows the closed molds and boxesabove the path of the discharge yoke at Station V.

FIG. 23 shows the elevator raised through the discharge yoke intoengagement with the lower section of the sand mold, the completed moldbeing held against the elevator by the opposed pressure plate at StationV.

FIG. 24 shows the upper pressure plate acting on the sand mold to pushit from the boxes and to lower it on the elevator to the level of thedischarge table and within the discharge yoke. 1

FIG. 25 shows the mold assembly advanced by the discharge yoke, pushingahead of it across the discharge table the mold assemblies previouslyformed, and leaving the elevated, molding boxes empty for cleaning andre-use at Station I.

DESCRIPTION OF PREFERRED EMBODIMENT The number of working stations aboutthe turntable 2 may be varied to suit the requirements. In the instantdisclosure, there are five stations designated by Roman numerals I to V.

The annular turntable 2 has rollers 3 guiding it for rotation about afixed post 4, the turntable being supported on rollers 5 which are inannular series beneath it (FIG. 2). Carried by the turntable is anannular indexing plate 6 shown in dotted lines in FIG. 1. This plate hasshoulders at 7 corresponding in number to the number of stations anddisposed to be engaged by the head 8 on ram 10 for the stepped indexingadvance of the turntable through an angle equal to the angular spacingbetween stations. In accordance with conventional practice, stops 11 aredesirably provided to assure accuracy of registration.

It is also desirable to provide an interlock to assure that theturntable will not be indexed until the operations at all of the severalstations have been completed. If the indexing is controlled manually,this may involve no more than the provision of push buttons at theseveral stations which cause illumination of a succession of lights totell the operator who controls ram 10 that all is in readiness for theindexing operation. If the operation is controlled mechanically, therecan be signals given at the several stations which are connected inseries in the circuit which energizes ram 10. Thus the relay circuitwill be completed to energize ram 10 only when all of therelays areenergized.

The turntable 2 is provided with pattern plate racks 12 corresponding innumber to the number of stations. Each rack is equipped with rollers 14upon which the respective pattern plates 16 may roll between an advancedposition for use and a retracted position for storage. In the retractedposition, each pattern plate is on the turntable 2. In the advancedposition, the pattern plate has left the turntable under thrust of a ramas shown at Station I in FIG. 1. The pattern plates carry appropriatepatterns 18.

Projecting radially from the turntable 2 are pairs of arms 20 forsupporting between them pairs of mold boxes 22, 24 which can be rotatedin unison for ninety degrees, and can be brought together and separatedas best shown in FIGS. 7 and 8. The arms 20 support bearings 26 fortrunnions 28 which support guide channels 30, one of which is shown atthe left in FIG. 8, it being understood that a similar arrangement is atthe right. Reciprocable in each guide channel is a bearing block 32which normally is in a position opposite the trunnion. This position isdefined by impositive detents consisting of the springpressed balls 34engaged in pockets 36 in the opposite faces of block 32. The block iselevated from this position by ram 80 at only one of the severalstations and this ram controls its return movement.

Carried by each block 32 is a transverse angle bar 42 which supportsrollers 44 providing a way along which shown in FIG. 8. A ram 52connected with the box 24 has its plunger 54 engaged with block 32 forthe raising and lowering of box 24. Similarly the ram 56 connected withbox 22 has its plunger 58 connected with block 32 for the raising andlowering of box 22.

For bodily rotation of the mold box assembly, a motor 60, preferably afluid pressure motor, has its output shaft 62 connected with trunnion 28to turn the guide channel 30 through an arc of 90 to move the boxassembly from the position shown at the left in FIG. 2 to the positionshown at the right of FIG. 2 (and return). Flexible hose connections 64are used as leads to the various rams and to the motor 60 and to thevent chambers 66 and 68 provided in the ends of boxes 22 and 24. Throughcertain of the hose connections, air escaping from the boxes while theboxes are being filled with sand is carried to a three-way valve 70having an atmospheric exhaust port 72. Later, when it is desired todischarge the molds from these boxes, the valve 70 connects the chambers66 and 68 with fluid supply line 74.

At Station ll, boxes 22 and 24 previously assembled on the pattern plate16, are filled with sand. As already stated, these boxes are open ended.When assembled with the pattern plate 16, they are rotated to stand onedge as shown in FIGS. 3, 4 and 5 and the whole assembly is thenelevated by the ram to engage the filling port 82 at the end of each boxwith the respective sand supply nozzle 84. Sand will be supplied throughnozzles 84, preferably in accordance with the disclosure of thecompanion application above identified. However, before the sand can beadmitted to the boxes,

the open ends of the boxes must be closed. The opposing ram heads 88have spring biased seal frames 90 which engage the margins of the boxesabout their open ends before the surfaces 92 of the heads 88 close theboxes. Sand is then injected under pressure as indicated by the arrows94 in FIG. 4, the air within the boxes escaping through the chambers 66and 68 and the hoses 64 to the three-way valve 70 and being dischargedthrough the exhaust 72 to the atmosphere.

When the boxes are completely filled with sand about the pattern 18, therams 88 are further advanced from the positions of FIG. 4 to thepositions of FIG. 5 The seal frames 90 cannot partake of the advance,being engaged with the respective boxes. However, the ram faces 92 passtelescopically into the boxes as shown in FIG. 5 to compress the sand.When this has been accomplished, the rams 88 are retracted to theinitial positions in which they are illustratedin FIG. 3 and thesand-filled boxes 22 and 24 are lowered from the position of FIG. 3 tothe position of FIG. 2. They are now free to rotate ninety degrees sothat they will be horizontal as in FIG. 8 instead of upright as in FIGS.2 to 5.

The sequence of operations is illustrated diagrammatically in FlGS. 9 to25.

At Station I, the boxes and patterns are cleaned of sand from theprevious operation. This may be done by any convenient means such as theair jets 96. The pattern plates 16 and the pattern mounted thereon arethen slid forwardly on the supporting rolls above described by a ram 15which moves the pattern plate from the storage rack 12 on the turntableto the rollers 44 on the arms 42 which are parallel to and interdisposedupwardly.

dotted lines in FIG. 10.

The open ended boxes 22 and 24 are now closed upon the pattern plate 16,as shown in FIG. I 1.

The turntable then indexes to advance the closed assembly of FIG. 11 toStation II. Here the motor 60 is energized to rotate the box assemblyfrom its initial horizontal position to the on-edge position shown inFIG. 12 so ports 82 for the filling of each box are Operation of ram 80now lifts the assembly from the position of FIG. 13 to the position ofFIG. 14 to engage the box sides about ports 82 with the filling nozzles84.

Immediately the closure rams 88 move in to engage the seal rings 90 withthe margins of the boxes and to dispose the closure surfaces 92 acrossthe initially open endsof the boxes. With the parts in the position ofFIG. 4, sand is injected through the nozzles 84 and the air displacedfrom the boxes escapes to atmosphere through the valve 70 as abovedescribed.

The boxes being completely filled with sand as shown in FIG. 14, therams 88 are advanced further as indicated in FIG. 15 to compact the sandaround the respective patterns 18. Rams 88 are then retracted out of theboxes and the elevator ram 80 is lowered to restore the box assembly toits original height. It is preferably at this point, with the boxesstill on edge, that the sprue basin or opening 100 is formed in anydesired manner (indicated diagrammatically by reamer 101). The motor 60is then reversed to restore the boxes to their initial horizontalposition as shown in FIG. 17. This occurs, desirably, at Station lll.

Still at Station III, the rams 52 and 56 are actuated to.

I the boxes 22 and 24 and to restore it to the storage rack on theturntable (FIG. 19).

The turntable now indexes to move the boxes and molds to Station IV andthe cores 108, if any, are positioned in the openings 110 left by thepatterns 18 (FIG. 20). This operation is usually manual. Still atStation IV, the box 24 is now engaged with box 22 to close the mold(FIG. 21).

The assembly of boxes and mold is still supported on the turntablearms20 at a level higher than that of the discharge table 112. When theturntable has rotated to bring the assembly to Station V, a normallyretracted withdrawal yoke 114 which is U-shaped in plan is advanced fromthe position of FIG. 22 to that of FIG. 23 where it is positioned toreceive the finished sand molds. At this point, the table 116 ofelevator ram 118 is raised through the yoke into engagement with thesand mold 120 which is in box 22. At the same time, a complementaryejector plate 122 of ram 126 moves down into engagement with the sandmold 128 which is in box 24. The movement of the ejector plate 122continues, forcing downwardly the molds 128 and 120 and the elevatortable 116 until the table registers with the withdrawal table 112 asshown in FIG. 24. The completed mold is now in the plane of yoke 114.The boxes 24 and 22 are empty. The discharge of the finished molds fromthe boxes may be facilitated by the use of the three-way valve '20 toconnect the pressure line 74 through hoses 64 with the respective ventcham bus 66 and 68 (FIGS. 7and 4).

Still at Station V,'the yoke 114' is moved by its ram toward the left asviewed in FIGS. 24 and 25, thereby withdrawing the mold from table 116of elevator 118 beneath the boxes 22 and 24. Movement of the mold justfinished in the direction of withdrawal across the table 112 propels inadvance of it on said table the molds previously delivered to the tablein the manner described (FIG. 25).

The next indexing movement of the turntable 2 restores the boxes whichhave been under discussion back to Station I in readinessfora repetitionof the sequence. It will be understood that in each of the five selectedpoints on the turntable which registers with the five stations abovedescribed, there is a similar series of boxes and similar controlmechanism so that with each periodical indexing movement another mold iscompleted and withdrawn for the pouring of metal into its sprue opening.

If desired, the method herein disclosed may be practiced by replacingpermanent boxes for flaskless molds with frames to receive tightfl'askswhich will produce tight flask molds. l l

The operation would stillinvolve the ninety degree rotation of theflask-carrying frames in exactly the manner in which the permanent boxesare rotated in the manufacture of flaskless molds. The operation willthen be as follows:

At Station I tight flasks and pattern will be positioned, assembled androtated ninety degrees. The operations at the other stations will be asdescribed except at Station V the complete tight flask mold will bedischarged instead of pushing out the flaskless mold as ports with thesupply nozzles. At Station lll, sand will be injected thus making themold exactly as above described. At-Station IV, the assembly will berotated back ninety degrees and the cope moldwill be drawn and pusheddown a conveyor to a remote closing station. At Station V, the drag moldwill be lowered'from the pattern and pushed down a conveyorto theclosing station, the pattern thereupon being transferred back to StationI. There can be any desired number of core setting stations toaccommodate additional core setters when the core setting time exceedsthe machine cycle time.

Obviously, from a method standpoint, the significant ninety degreerotation is exactly the same as above described and it serves the samepurpose.

Iclaim:

1. A method of making a sand mold which comprises the steps of making anassembly of form boxes by superposing the form boxes on an interposedgenerally horizontal pattern plate, rotating the assembly to positionthe pattern plate in a generally vertically position, covering the openfaces of the form box with platens constituting temporary facestherefor, propelling sand into the form box, compressing the sand in theform box to constitute a mold, withdrawing the platens and returning theassembly to a position with the pattern plate generally horizontal, andremoving the pattern plate.

2. A method of making a sand mold, said method comprising the steps ofmaking an assembly of form boxes and a pattern plate by superposing theform boxes upon an interposed pattern plate, the boxes having sandreceiving openings in their ends and after the assembly is made theboxes are turned on end and the respective openings are registered withand engaged by filling nozzles through which the sand is introduced.

3. A method according to claim 2 in which the boxes have no facesopposed to the pattern'plate and are temporarily closed by platensfitting their respective margins at opposite sides of the pattern plateduring the introduction of sand into the boxes, the said platens beingthereafter advanced concurrently in opposite directions toward thepattern plate to compress the sand with which the boxes have beenfilled.

4. A method according to claim 3 in which the said platens are withdrawnfrom the boxes and the boxes and their sand mold contents are restoredto horizontal and separated, the pattern plate being thereupon removedand the boxes and their sand mold contents are reassembled.

5. A method according to claim 4 including the further steps ofconfining the sand mold contents of the boxes between upper and lowerplatens and effecting relative movement between the boxes and the sandmold contents thus confined, thereby ejecting the sand mold contentsfrom the boxes.

6. A method of making a mold including the step of making a box bymaking an assembly of two open form boxes upon a pattern plate inhorizontal position and turning the assembly on end, and disposingthebox between platens providing temporary top and bottom for the box, thefilling of the box with sand involving the introduction of sandindependently into the respective form boxes at opposite sides of thepattern plate, the advance of the platens producing compressed sandmolds in the respective form boxes, and removing the pattern plate andthereafter assembling compressed sand molds made in the form boxes, andremoving the assembled compressed sand molds from the assembly of formboxes.

UNITED STATES PATENT oFFIc-E CERTIFICATE OF CORECTION I Patent No.3,730,250 Dated May 1, 1975 Inventor(s) Harrison E. Fellows It iscertified that error appears in the above-identified patent and thatsaidLetters Patent are'hereby corrected as shown below:

Column 1, line 7, after "No. 355,285" insert issued March 18, 1969Column 1, line 55, insert pivotally between the words "trunnions" and"carried' Column 5, line. 35', insert roviding a way after Y "rollers; lt

Column 5, lines 6 8c 7, delete the entire sentence--- Ihe turntable thenindexes to advance the closed assembly of Fig. 11 to Station II.

Column 5, line ll, after upwardly. insert the following sentence Theturntable'then indexes to advance the closed assembly of Fig. ll toStation II.

Signed and sealed this 29th day of January 1974.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER Attesting Officer ActingCommissioner of Patents FORM P0-10 0 (10-69) I USCOMM-DC 6037B-P69 w 1U.S. GOVERNMENT PRINTING OFFICE: IBIS 0-366-334.

1. A method of making a sand mold which comprises the steps of making anassembly of form boxes by superposing the form boxes on an interposedgenerally horizontal pattern plate, rotating the assembly to positionthe pattern plate in a generally vertically position, covering the openfaces of the form box with platens constituting temporary facestherefor, propelling sand into the form box, compressing the sand in theform box to constitute a mold, withdrawing the platens and returning theassembly to a position with the pattern plate generally horizontal, andremoving the pattern plate.
 2. A method of making a sand mold, saidmethod comprising the steps of making an assembly of form boxes and apattern plate by superposing the form boxes upon an interposed patternplate, the boxes having sand receiving openings in their ends and afterthe assembly is made the boxes are turned on end and the respectiveopenings are registered with and engaged by filling nozzles throughwhich the sand is introduced.
 3. A method according to claim 2 in whichthe boxes have no faces opposed to the pattern plate and are temporarilyclosed by platens fitting their respective margins at opposite sides ofthe pattern plate during the introduction of sand into the boxes, thesaid platens being thereafter advanced concurrently in oppositedirections toward the pattern plate to compress the sand with which theboxes have been filled.
 4. A method according to claim 3 in which thesaid platens are withdrawn from the boxes and the boxes and their sandmold contents are restored to horizontal and separated, the patternplate being thereupon removed and the boxes and their sand mold contentsare reassembled.
 5. A method according to claim 4 including the furthersteps of confining the sand mold contents of the boxes between upper andlower platens and effecting relative movement between the boxes and thesand mold contents thus confined, thereby ejecting the sand moldcontents from the boxes.
 6. A method of making a mold including the stepof making a box by making an assembly of two open form boxes upon apattern plate in horizontal position and turning the assembly on end,and disposing the box between platens providing temporary top and bottomfor the box, the filling of the box with sand involving the introductionof sand independently into the respective form boxes at opposite sidesof the pattern plate, the advance of the platens producing compressedsand molds in the respective form boxes, and removing the pattern plateand thereafter assembling compressed sand molds made in the form boxes,and removing the assembled compressed sand molds from the assembly ofform boxes.